Process and device for converting a continuous tow of artificial filaments into a sliver comprising staple lengths



J1me 1956 I 1. F. STEWART ET AL 2,748,427

PROCESS AND DEVICE FOR CONVERTING A CONTINUOUS TOW OF ARTIFICIAL FILAMENTS INTO A SLIVER COMPRISING STAPLE LENGTHS Filed Sept. 11, 1955 FIG. 1.

INVENTORS.

IAN FRASER STEWART JOHN BRYAN SEED ATTORNEYS WM W United States Patent PROCESS AND DEVICE FOR CONVERTING A CON- TIN UOUS TOW OF ARTIFICIAL FILAMENTS INTO A SLIVER COMPRISING STAPLE LEN GTHS Ian Fraser Stewart and John Bryan Seed, Dumfries, Scotland, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain Application September 11, 1953, Serial No. 379,564

Claims priority, application Great Britain October 20, 1952 3 Claims. (Cl. 19--.48)

The present invention relates to a process and a device for converting a continuous tow of artificial filaments into a sliver comprising staple lengths.

The object of the present invention is to provide a simple process and device for the production of a sliver of parallel filaments uniformly distributed along the length of the sliver and which approximate in length to a predetermined staple length and are situated with respect to each other in the sliver so that the ends of neighbouring filaments do not lie adjacent to each other thereby saving the expense of cutting, teasing, carding, preparing, combing and several gillings in separate and independent machines.

The invention is particularly applicable to the conversion of imperfect tows wherein the constituent filaments do not lie exactly side by side and in correct parallel relation to each other as they would immediately after issue from the extrusion die, but are to some extent entangled by lateral crossing and consequent interlinking of neighbouring filaments. It is also applicable to tows bearing a small amount of knotted, nepped, or balled filament such as occurs when filaments are broken and the ends displaced along the tow, and to tows which carry some foreign inclusions such as fibrous dust or fly, and granular dust or sediment.

An imperfect tow cannot be made into a satisfactory sliver and so for example into an acceptable top without being subjected to such combing action as is part of conventional worsted manufacture, namely that of drawing through a suitable batch of pins to remove undesirable matter and fibre formations, and to lay in correct parallel arrangement the remaining filaments.

Previous proposals for the conversion of a continuous travelling tow of artificial filaments into a sliver comprising staple fibres have been based upon a supply of perfect tow, that is to say, tow which is open or free from cross links or lateral entanglement and which is without nepped or balled filaments or foreign inclusions. Such prior proposals have depended upon methods of cutting or breaking to length and of causing relative longitudinal slip between the resulting staple fibres.

The principle underlying the present invention is to perform the necessary combing of even imperfect tow in such a way as to result in the least possible loss of fibre through breakage.

According to the present invention the process for the conversion of a continuous tow or band of endless filaments into a sliver comprising staple fibre comprises repeating the cycle of operations of combing from the free end in steps of progressively greater length a forwardly metered length of said tow or band, cutting the thus combed and opened metered length to desired staple length, and forwardly metering as measured from the cut end a sufiicient length of tow or band for combing and subsequent cutting into staple length as aforesaid.

The present invention results from having appreciated :that a group of fibres can only be combed from a position relatively close to the end of the tow of which they are a part, because, should the comb be inserted far from the end, there results a lock-ing of any crossed filament lying on opposite sides of a tooth of the comb, which causes resistance to the passage of the comb and makes irregular and nepped masses of debris.

A device according to the invention comprises in association metering means for intermittently forwardly metering a length of a continuous tow or band of filaments, means for combing said metered length from a free end by steps of progressively greater length, and means for cutting the combed and opened metered length into staple of desired length.

If desired said device may also include means for collecting and laying the opened and paral'lelised staple lengths non-conterminously for subsequent gilling.

The said metering means, means for combing, and means for cutting function in timed sequence to one another.

The said means for combing for example can comprise an end-less conveyor provided with means for driving it at a steady speed and having thereon a number of flat plates mounted in step formation by pivoted links, wherein the direction of movement of the conveyor is such that each step moves with the re-entrant angle between the plate and the riser of the preceding step leading, wherein with the exception of one plate each of the other plates has fixed thereon a strip of card clothing with its wires inclined towards said reentrant angle, wherein the strips on the two plates immediately preceding the plate without a strip are each preferably longer than the desired staple length, wherein the strip on the plate on the other side of the plate without a strip is of shortest length, wherein the intermediate strips are preferably evenly intergraded in length, and wherein each of said strips is attached to its plate preferably with its leading edge close to said angle.

Two combing strips having substantially the same maximum effective lengths are provided to ensure that any debris left by the longest combing strip which first does the longest combing is removed by the longest combing strip which follows it.

The continuous sliver produced according to the invention can either be converted into top form or can be used for spinning into yarn without the intermediate formation of a top. I

The invention is illustrated by way of example with reference to the diagrammatic drawing accompanying the specification wherein Fig. l is a side elevation of one embodiment of apparatus according to the invention and Fig. 2 is an extension of Fig. 1 at the end of the small conveyor for collecting the cut and combed tow. In accordance with the embodiment illustrated in the drawing flat plates or steps 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 are mounted on an endless conveyor 11 by pivoted links 12 in such a way that they form a continuous series of steps. The conveyor 11 is carried on and driven at a steady speed through wheels 13 and 14 in the direction 15 so that the steps move with the re-entrant angle 16 between the plate and the link leading. On plates 1, 2, 3, 4, 5, 6, 7, 8 and 9 are fixed strips of suitable card clothing 17 with their wires inclined towards the angle 16. Of the strips, that on step 1 is the shortest and that on steps 8 and 9 are equal and slightly longer than the desired staple length. The intermediate ones are evenly intergraded in length. They are all attached to the plates with their leading edge close to the angle 16. Plate 10 is devoid of card clothing. Rubber covered feed rollers 18 are driven intermittently in the direction 19, while the roller 20 has axial ridges along its surface and is held against rollers 18 by the combined action of spring loaded bearings 21 and the tension in the .the stepped conveyor.

An electrically operated barbers hair clipper 24 is included in the machine to cut the tow 22 at the correct moment in the cycle of operations and at such a position as the section 25 of the tow between the feed rollers and A length of tow 26, which has been combed by the strips 17, is cut from the feed tow 22 by the clipper 24 at such a moment in the cycle that it is left partly in the. wires of the strip of card cloth- .ing on plate 9 and partly overhanging the end of plate 9. The small conveyor 27 is placed so that the free end of the cut length of tow 26 will fall over and lie on its upper surface when the stepped conveyor has moved plate 9 partly round the curve of wheel 13. A flat bar 28 is fixed to arm 29 which is pivoted at 30 so as to be capable of swinging until it presses the overhanging end of the cut tuft 26 tightly against the small conveyor 27. Feed rollers 31 are placed to grip and deliver the accu mulation of combed material 32 from the small conveyor 27 A device 33 with a single row of suitably inclined combing .pins 34 at the same lateral pitch setting as the points on the strips of card clothing, is designed to act with a reciprocating motion so that it clears any debris of broken fibres from the combing strips as these pass its station.

The operation of the machine is as follows. It is run until plate 10 lies beneath the dabber, and then stopped. The tow 22 is passed through the feed rollers 18 and 20, and over to the dabber 23, and is cut off at the edge of the dabber remote from the feed rollers. The machine is then set in motion. While the feed rollers remain stationary, the dabber descends each time a step passes just beyond its edge and presses the end of the tow against the points on the card clothing 17. These points being suitably inclined, the filaments of the tow are pulled down into the wires, and the end of the tow is combed by these. As each succeeding step passes, a longer portion of the end of the tow is combed, until a little more than the full staple length has been processed. The duplication of the longest combing strip, on step 9, ensures that any debris brought over from step 8 is finally extracted.

When the combed material has been partly drawn through the pins on step 9, the clipper 24 descends and severs the end staple length which is then carried away by the card strip 17 on step 9 with a part of its length overhanging the blank step 10, and the feed rollers 18 and 20 promptly make good the length 26 cut off by metering the tow forward the correct distance. The stepped conveyor 11 as it continues its motion repeats the progressive combing on the end of the fed tow, and at the same time carries the cut piece 26 on step 9 round the curve of the wheel 13, until the free end falls over on to the small conveyor 27. There it is immediately held fast by the swinging bar 28, which presses it firmly against the conveyor 27. Step 9 now recedes and so completes the combing. The bar 28 lifts, and conveyor 27 moves a short distance in readiness to receive the next combed and cut tuft from the stepped conveyor, and the delivery rollers 31 gradually feed the resulting aggregate of slightly overlapping tufts 32 to the fallers of an intersector gill, or some such device.

The pinned cleaning device 33 acts continuously to keep the combing strips 17 free from waste fibre.

The configuration of the feed apparatus is such that any increase in the tension in the tow 22 will automatically increase the grip between the rollers 18 and 20 by pulling roller 20 more tightly against the rollers 18, and so prevent the tow from being dragged through.

The dabber 23 acts at every step except the blank one, 10, at which part of the cycle of operation of cutting and feeding is being performed.

The length of tow combed is slightly greater than the staple length to be cut ofi in order to prevent any undesirable material in the uncombed portion of the tow coming into contact with the clipper and perhaps being taken forward with the finished tuft.

What we claim is:

1. A device for the conversion of a continuous tow of endless filaments into a sliver of staple fiber comprising in combination means for intermittently feeding a predetermined length of a continuous tow of filam-ents forwardly to a combing station, means at said combing station for combing said predetermined length of continuous tow from a free end thereof by steps of progressively greater length while said tow is held stationary by said feeding means, and means for cutting the combed and opened predetermined length of said tow into staple of desired length, wherein said means for combing comprises an endless conveyor having means for driving said conveyor at uniform speed and having on said conveyor a plurality of flat plates mounted in step formation by pivoted links, certain of said plates bearing combing elements thereon and extending over successively difieren-t lengths of the different plates, and wherein the spacing and direction of movement of said conveyor in relation to said feeding means is such as to bring the combing elements on the ditferent plates successively into engagement with said tow for combing the same while held by said intermittent feeding means.

2. The device of claim 1 wherein the combing elements on certain of the plates extend over lengths thereof exceeding the desired staple length.

3. The device of claim 1 wherein the combing elements on the plates extend over evenly graduated portions of the lengths thereof.

References Cited in the file of this patent FOREIGN PATENTS 

1. A DEVICE FOR THE CONVERSION OF A CONTINUOUS TOW OF ENDLESS FILAMENTS INTO A SILVER OF STAPLE FIBER COMPRISING IN COMBINATION MEANS FOR INTERMITTENTLY FEEDING A PREDETERMINED LENGTH OF A CONTINUOUS TOW OF FILAMENTS FORWARDLY TO A COMBING STATION, MEANS AT SAID COMBING STATION FOR COMBING SAID PREDETERMINED LENGTH OF CONTINUOUS TOW FROM A FREE END THEREOF BY STEPS OF PROGRESSIVELY GREATER LENGTH WHILE SAID TOW IS HELD STATIONARY BY SAID FEEDING MEANS, AND MEANS FOR CUTTING THE COMBED AND OPENED PREDETERMINED LENGTH OF SAID TOW INTO STAPLE OF DESIRED LENGTH, WHEREIN SAID MEANS FOR COMBING COMPRISES AN ENDLESS CONVEYOR HAVING MEANS FOR DRIV- 